Culture media for starter production

ABSTRACT

Starter cultures are produced using a culture medium containing undecalcified sweet whey, undecalcified nonfat dry milk, a nitrogen source and a citrate source. The medium provides the advantages of greater reliability, higher viable bacteria number, and higher acidities in a shorter time. Due to enhanced activity of starter cultures produced on the medium, only about 0.75 to about 1 part starter culture per 100 parts of milk is required in making cheese.

United States Patent [1 1 Anderson et al.

[ 1 Dec. 3, 1974 CULTURE MEDlA FOR STARTER PRODUCTION [76] Inventors:Delmar L. Anderson, 208 Blueberry Ln., Syracuse, NY. 13219; Louis R.Boston, 1802 Chestnut Ridge Rd., Chittenango, NY. 13037; William A.Seleen, 200 Dewitshire Rd., De Witt, NY. 13214 [22] Filed: June 5, 1972[21] Appl. No.: 259,862

[52] US. Cl 195/100, 426/36, 426/41,

426/43 [51] Int. Cl. ..'Cl2k 1/10, Cl2k 3/00 [58] Field of Search99/115, 116, 59; 195/100, 195/36; 426/43, 41, 185

[56] References Cited UNITED STATES PATENTS 3,048,490 8/1962 Lundstedt426/43 X 3,354,049 11/1967 Christensen 99/116 X OTHER PUBLICATIONSHammer, et al., Bacteriology of Butter Cultures, .1.

Dairy Sci., vol. 26, No. 2, 1943, (pp. 92-97 and 136-138) SF 221J8.

Sandine et al., Influence of Milk Cittate Concentration on AssociativeGrowth of Lactic streptococci, J. Dairy Sci., Vol. 47, 1964, (p. 110) SF221.18.

Primary Examiner -David M. Naff Attorney, Agent, or Firm-George P.Maskas; George A. Kap; Donavon L. Favre 5 7] ABSTRACT 5 Claims, NoDrawings CULTURE MEDIA FOR STARTER PRODUCTION BACKGROUND OF THEINVENTION added to a culture media to generate a pleasant tastingcomponent which is subsequently added to a cheese product. The prior artin this area is exemplified by US. Pat. No. 2,971,847 of Babel.Generally speaking the prior art has resulted in a slower than desiredgrowth of viable bacteria and erratic viable bacterial count after theinitial growth period.

SUMMARY The present invention is based upon a culture media containingadded citrate and which does not require decalcified milk or theaddition of simple sugars or internally generated carbohydrates. Inaddition the culture medium of thepresent invention results in fastgrowth of bacteria, and retention of high viable bacterial populationsthroughout the incubation period.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The culture media of thepresent invention based, upon 100 parts of ingredients consistsessentially off a. from 10 to 99 parts of a milk product selected fromthe group consisting of sweet. whey, non-fat dry milk, sour whey powder,buttermilk powder, whole milk powder, and mixtures thereof. The milkproduct is undecalcified and contains at least one part of calcium perthousand parts of milk product. The culture media also contains: b. fromabout 0.1 to about 30 parts of a nitrogen source;

. from about 1 to about 30 parts, based upon citrate anion exclusive ofcation weight, of an added citrate source selected from the groupconsisting of citric acid and salts of citric acid. The salts arepreferably the ammonium or alkali metal salts of citric acid such assodium or potassium salts, but may also be other water soluble non-toxicsalts of citric acid. It is preferable that the milk product be presentin an amount from about 7010 95 parts. The above composition provideshigher bacterial counts than prior art starter culture mediacompositions and also provides a greater uniformity of bacterial counts.The result is that the starter cultures produced using the culturemedium can be used sooner than the prior art systems with more favorableresults or later than the prior art systems with more favorable resultsthan heretofore known.

Another advantage of the present system is that sweet whey can be usedas the milk product, and bacterial counts, higher than those normallyobtained with the non-fat dry milk of prior art systems, can beachieved. It is preferred that the major component of the milk productbe sweet whey and that a minor component of the product be non-fat drymilk.

The nitrogen source is selected from the group consisting of yeastextract, yeast autolysate, solubilized yeast, food yeast, amino acids,proteins and mixtures thereof. There are many yeast productscommercially available. The yeast products and the companies whichsupply them commercially are as follows: Ardimine YEP, Yeast Products,Inc., 455 Fifth Ave., Paterson, N.J.; Lake States Torula Yeast, St.Regis Paper, Rhinelander, Wis.; Yeast Autolysate, Universal Foods, 433East Michigan Street, Milwaukee, Wis. 53039; and Yeatex, CalvertVavasseur and Co., Inc.', 19 Rector Street, N.Y., N.Y.; YeastAutolysate, Amber Labs, Juneau, Wis. 53039; and Maggi Standard LightPowder, Nestle Co., White Plains, NY.

The yeast product or other nitrogen source preferably is present in anamount of from 0.5 to 10.0 parts.

It is preferable that the citrate source be present in an amount of fromabout to 20 parts. At the 20 part level good phage inhibition is takingplace. The preferable citrates are the ammonium citrate, sodium citrate,

1 potassium citrate and citric acid. Sodium citrate is the mostreadilycommercially available form and provides good buffering activity.The production of high quantities of lactic acid in the starter cultureand the maintaining of a good bacterial flora is related to thebuffering capability of the citrate present. Sodium citrate has 1 vis,Leuconostoc citrovorum, Lactobacillus delbrueckii,

Lactobacillus fermenti, Lactobacillus helveticus, Lactobacillus lactis,Lactobacillus plantarum, Lactobacillus thermophilus, Leuconostocmesenteroides, Propionibacterium species, and mixtures thereof.

The bacteria which are normally used in cheese manufacture, which arepreferable here are Streptococcus cremoris, Streptococcus lactis,Streptococcus citrovorus, Propionibacterium shermanii and mixturesthereof.

The starter culture which has been prepared is used in much the'same wayas conventional starter cultures have been used in the past. Onenoticeable difference is that less of the present starter culture isnecessary than prior arts starter cultures. For example, it isrecommended that 0.75 part of the present starter culture he added toparts of milk. Conventionally, one part was required. Other noticeabledifferences are that the present starter culture can be used soonerthan, or later than, conventional starter cultures with far less adverseresults than one normally encounters using the prior art startercultures.

In the following examples, as elsewhere in the Specification and claims,all parts are by weight unless specifically expressed otherwise. Acidityis developed titratable acidity expressed as lactic acid.

EXAMPLE I A culture media was prepared by dry blending the followingingredients:

69 parts of sweet whey 16 parts of non-fat dry milk 1 part of yeastextract 14 parts of sodium citrate To 89 parts of water at 110F wereadded 11 parts of the dry culture medium. Heating was continued topasteurize the mix and in combination with agitation, to aid in propermixing. After the dry mix was dissolved, the solution was then heated to185F and held at that temperature for 40 minutes. The solution was thenrapidly cooled to 70F. The solution was inoculated with a mother cultureof Streptococcus lactis and Streptococcus cremoris. The ratio of motherculture to solution was 0.75 part of mother culture per 100 parts ofsolution. The cultured solution was incubated at 72F to produce astarter culture.

For comparison purposes a second starter culture was prepared in exactlythe same manner except that ll parts of dry non-fat milk were used asthe culture media and added to 89 parts of water.

Over a 24 hour period, measurements were made of lactic acid produced,the number of live bacteria present per cc and pH. The sodium citratecontaining starter culture provided a superior buffered system, higherlactic acid production and higher bacteria counts over the 24 hourperiod than the starter culture employing non-fat dry milk.

Cheddar and Colby cheeses were made using 1 part of the above describedstarter culture, which had been incubated for 16 hours, per 100 parts ofmilk. The cheeses made using the sodium citrate containing starterculture cured in less time than the cheeses made using a starter culturebased upon non-fat dry milk.

EXAMPLE 2 A starter culture was prepared in the same manner as set forthin Example 1 except that the dry mix contained 6 parts of sodium citrate24 parts of non-fat dry milk 1 part yeast extract 69 parts of sweet wheyThe acidity of the starter culture at the end of 8 hours of incubationwas 0.42. A starter culture prepared in the same way except that drynon-fat milk was used instead of the dry mix, at the same time had 0.3.This example indicates how much faster acid is produced-using thecitrate containing media as compared .to a conventional media.

EXAMPLE 3 A starter culture was prepared in the same manner as set forthin Example 1 except that the dry mix contained 10 parts of sodiumcitrate 1 part yeast extract 23 parts non-fat dry milk 66 parts sweetwhey The acidity of the starter culture produced at the end of the 8hour incubation period was 0.49. Similar enhanced results were obtainedusing l4, l7 and part citrate mixes containing one and 2 parts of yeast.

EXAMPLES 4 10 Example 4 Composition Lactic acid produced at the end of24 hours 10 parts sodium citrate 1 part yeast extract 23 parts non-fatdry milk 66 parts sweet whey nonfat dry milk Composition Lactic acidparts sodium citrate part yeast extract parts non-fat dry milk partssweet whey parts sodium citrate parts yeast extract parts non-fat drymilk parts sweet whey parts sodium citrate part yeast extract partsnon-fat dry milk parts sweet whey parts sodium citrate parts yeastextract parts non-fat dry milk parts sweet whey parts sodium citratepart yeast extract parts non-fat dry milk parts sweet whey parts sodiumcitrate parts yeast extract parts non-fat dry milk parts sweet whey Thefollowing table sets forth the enhanced capability of the citratecontaining starter culture to produce EXAMPLES ll 14 high bacterialcounts. The starter cultures were produced by the same method set forthin Example 1.

Ex. Composition Bacterial count in live cells/cc l 1 l0 parts sodiumcitrate 330x10 1 part yeast extract at 16 hours 23 parts non-fat drymilk incubation 6 parts sweet whey l2 Comparative Example 107x10 usingdry non-fat at 16 hours milk solids incubation l3 17 parts sodiumcitrate .from 10 to 2 parts of yeast extract 16 hours the 12 partsnon-fat dry milk count remained 69 parts sweet whey above one billion I420 parts of sodium citrate from 10 to 2 parts of yeast extract 16 hoursthe count remained above one billion EXAMPLES 15 19 Ex. CompositionResults l5 69 parts sweet whey 24 parts non-fat dry milk 6 parts sodiumcitrate 1 part yeast extract Fair to good 66 parts sweet whey Good 23parts non-fat dry milk I part yeast extract 10 parts sodium citrate 69parts sweet whey l5 parts non-fat dry milk 2 parts yeast extract 14parts sodium citrate Best 69 parts sweet whey 12 parts non-fat dry milk2 parts yeast extract 17 parts sodium citrate 69 parts sweet whey 9parts non-fat dry milk 2 parts yeast extract 20 parts sodium citrateBest From the above Examples 19, it can be seen that the best resultsare obtained when at least 10 parts of citrate are employed. It can alsobe seen that higher quantities yeast extract favorably effect thequality of the starter culture and its applicability to the cheesemaking process.

We claim:

1. A culture media for producing bacterial starter cultures consistingessentially of on a dry basis:

a. from about 70 to 95 parts of a milk product consisting essentially ofa major amount of undecalcified sweet whey, and a minor amount ofundecalcified nonfat dry milk,

b. from about 0.5 to 10 parts of a nitrogen source selected from thegroup consisting of yeast extract, yeast autolysate, solubilized yeastand food yeast and,

c. from about one to about 30 parts, based upon citrate anion exclusiveof cation weight, of an added citrate source selected from the groupconsisting of citric acid and salts of citric acid, such ingredientsbeing combined in such a manner so as to provide about 100 total partsof ingredients.

2. The composition of claim 1 wherein the citrate source is present inan amount of from about l0 to about 20 parts. I

3. The composition of claim 1 wherein the citrate source is selectedfrom the group consisting of ammonium citrate, sodium citrate, potassiumcitrate and citric acid.

4. The composition of claim 1 wherein the citrate source is sodiumcitrate.

5. The composition of claim 1 wherein the mixture is dry.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3.852.158Dated December 3 1 74 lnventofls) Delmar Andersen, Louis Boston, WilliamSeleen It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Cover page column 1 "Anderson" should read "Andersen" Cover page column2 "Cittate" should read "Citrate" Signed and sealed this 4th day ofFebruary 1975.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents USCOMM-DC 60376-P69 U. 5. GOVERNMENT PRINTING OFFICE: I9690-366-334 FORM PO-105O (10-69)

1. A CULTURE MEDIA FOR PRODUCING BACTERIAL STARTER CULTURES CONSISTING ESSENTIALLY OF ON A DRY BASIS; A. FROM ABOUT 70 TO O 95 PARTS OF A MILK PORDUCT CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF UNDECALCIFIED SWEET WHEY, AND A MINOR AMOUNT OF UNDECALCIFIED NONFAT DRY MILK, B. FROM ABOUT 0.5 TO 10 PARTS OF A NITROGEN SOURCE SELECTED FROM THE GROUP CONSISTING OF YEAST EXTRACT, YEAST AUTOLYSTATE, SOLUBILIIZED YEAST AND FOOD YEAST AND, C. FROM ABOUT ONE TO ABOUT 30 PARTS, BASED UPON NITRATE ANION EXCLUSIVE OF CATION WEIGHT, OF AN ADDED CITRATE SOURCE SELECTED FROM THE GROUP CONSISTING OF CITRIC ACID AND SALTS OF CITRIC ACID, SUCH INGREDIENTS BEING COMBINED IN SUCH A MANNER SO AS TO PROVIDE ABOUT 100 TOTAL PARYS OF INGREDIENTS.
 2. The composition of claim 1 wherein the citrate source is present in an amount of from About 10 to about 20 parts.
 3. The composition of claim 1 wherein the citrate source is selected from the group consisting of ammonium citrate, sodium citrate, potassium citrate and citric acid.
 4. The composition of claim 1 wherein the citrate source is sodium citrate.
 5. The composition of claim 1 wherein the mixture is dry. 